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TI-2026-14980 Aliases CVE-2026-18209GHSA-c8xx-fr3x-6m5w

Keycloak-services: keycloak-services: oidc redirect_uri fragment bypass in http parameter pollution check

Priority LOW 22CWE-1288Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.

Summary

A flaw was found in the keycloak-services component of Keycloak, which handles OpenID Connect (OIDC) authentication flows. The issue occurs because the security check designed to prevent HTTP parameter pollution only inspects the query portion of a redirect URL and ignores the fragment portion. When a client is configured with a wildcard redirect URI, an attacker can use this to inject duplicate security parameters into the login response. If a client application is not configured correctly, it might trust the attacker's injected data instead of the real security information from Keycloak, leading to session fixation or account confusion.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00409 35th percentileScored 2026-11-07
Fix Fixed Red Hat: 2 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Red HatRed Hat build of Keycloak 26.6—26.6.7-3Patch availableCNA
Red HatRed Hat build of Keycloak 26.6—26.6-20Patch availableCNA
Red HatRed Hat build of Keycloak 26.6—26.6-20Patch availableCNA
Red HatRed Hat build of Keycloak 26.6.7——Not affectedCNA
Red HatRed Hat build of Keycloak 26.6.7——Not affectedCNA
Red HatRed Hat build of Keycloak 26.6.7——Not affectedCNA
Red HatRed Hat Data Grid 8——Not affectedCNA
Red HatRed Hat JBoss Enterprise Application Platform Expansion Pack——Not affectedCNA
Red HatRed Hat Single Sign-On 7——Not affectedCNA
  • Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6.7-3 Patch available CNA
  • Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6-20 Patch available CNA
  • Red Hat build of Keycloak 26.6 VendorRed Hat Affected — Fixed in 26.6-20 Patch available CNA
  • Red Hat build of Keycloak 26.6.7 VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat build of Keycloak 26.6.7 VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat build of Keycloak 26.6.7 VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat Data Grid 8 VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat JBoss Enterprise Application Platform Expansion Pack VendorRed Hat Affected — Fixed in — Not affected CNA
  • Red Hat Single Sign-On 7 VendorRed Hat Affected — Fixed in — Not affected CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:*not specified by NVDVulnerableRed Hat
  • cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:* Versions not specified by NVD Vulnerable ·Red Hat

Remediation

Red Hat 2 advisories

  • RHSA-2026:68277 Released 2026-09-16 · Red Hat rating Important
    Red Hat build of Keycloak 26.6.7 Images Security Update
    • Red Hat build of Keycloak 26.6 rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9-operator
  • RHSA-2026:68278 Released 2026-09-16 · Red Hat rating Important
    Red Hat build of Keycloak 26.6.7 Security Update
    • Red Hat build of Keycloak 26.6.7

Vendor assessments

Red Hat

Red Hat rating: Low. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat build of Keycloak 26.6Fixed RHSA-2026:68277
Red Hat build of Keycloak 26.6.7Fixed RHSA-2026:68278
Not affected: 3 products
  • Red Hat Data Grid 8
  • Red Hat JBoss Enterprise Application Platform Expansion Pack
  • Red Hat Single Sign-On 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-18209
  2. 2026-10-03 Alias added: GHSA-c8xx-fr3x-6m5w

References

Advisory 4

  • TI-2026-02223 Keycloak: keycloak: unauthorized authentication via disabled saml identity provider CVSS 3.1HIGH 8.1
  • TI-2024-01049 Keycloak: path transversal in redirection validation CVSS 3.1HIGH 8.1
  • TI-2026-13740 Keycloak-services: keycloak-services: saml idp-initiated broker login bypasses link-only restriction CVSS 3.1CRITICAL 9.8
  • TI-2026-13741 Keycloak-services: keycloak-services: saml broker metadata import disables response signature validation CVSS 3.1CRITICAL 9.1
  • TI-2026-13106 Keycloak-services: keycloak-services: dcr protocol mapper type-swap policy bypass allows privilege escalation CVSS 3.1HIGH 8.8
  • TI-2026-02631 Authentication bypass in Red Hat build of Keycloak 26.2 CVSS 3.1HIGH 8.8
See all 110 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences